Astrophysicists have observed, for the first time, a star being formed from another star. The primary star, catalogued as MM1A, is young and massive, and surrounded by an accretion disc of gas and dust. Researchers noticed a close, faint, counterpart, MM2A, orbiting the primary. By measuring the radiation and the frequency of light emitted by the gas and dust, they were able to weigh the infant star as being less than half the mass of the Sun."Stars form within clouds of gas and dust in interstellar space," said lead researcher Dr. John Ilee, from the School of Physics and Astronomy at the University of Leeds. "When these clouds collapse under gravity, they begin to rotate faster, forming a disc around them. In low mass stars like our Sun, it is in these clouds that planets can form. In this case, the star and disc we have observed is so massive that ... we are seeing [ in the disc ] another star being born."Dr. Duncan Forgan, a co-author from the Centre for Exoplanet Science at St. Andrews University, added: "I've spent most of my career simulating this process to form giant planets around stars like our Sun. To actually see it forming into something as large as a star is really exciting."